Large mainframe computer systems typically use a vast quantity of removable magnetic media, for example, tape reels or tape cartridges, for data storage. This media is usually located in a tape library, often separated from the computer room. Many of these large systems have tape management system software that partially automate the task of retrieving tape media for use by the computer system. The tape management system software generates a "pick list" which is given to a tape librarian who goes to the tape library and retrieves the media identified on the pick list. The librarian must take the pick list from the computer room, walk to the tape library, locate the media identified by the pick list, retrieve such media from its storage location, and walk back to the computer room with the media in hand. After the tape is used by the computer system, the librarian must take the tape back to the library and place it into a shelf location.
In most large computer systems tape media is stored in volume serial number order, which requires one shelf location for each tape volume serial number regardless of where the tape is currently located. In these large computer systems, many tapes, typically twenty percent, are stored in an off-site location to provide for data security. Also, many of these large computer systems now have automated tape library systems that store a quantity of tapes in a silo where they can be machine retrieved. The tapes stored in the machine retrievable silo are, of course, removed from the tape library while stored in the silo, and leave empty shelf space. Because of the off-site and machine retrievable silo storage, large quantities of library shelf space would be empty if the library reserved a shelf location for each tape. Therefore, a method is needed to easily separate the location of a tape in the library from its volume serial number.
If the tape media is not being stored in sequential location by tape volume serial number, each time a tape is placed back into the library the librarian must enter the location into which the tape is being placed. This requires manual entry of a shelf location by a librarian whose hands are full of tapes being placed into the library, and it requires that the manual entry be done while the librarian is in the library shelf storage area, not at a fixed location where a terminal is available.
Even if the librarian's hands are free, manual entry of the tape location is still subject to key entry error. Even a one percent error rate, in a library with a million volumes, would result in ten thousand lost tapes.
Similar problems exist with file folders in a typical office. Many offices today are storing important file folders at a secure off-site location. Also, inventory of file folders, because of the quantity involved, is much more difficult than tape media inventory.
There is need in the art then for a system to improve the reliability and efficiency of identifying the location of tapes in a tape library. There is a further need for such a system that automatically determines a storage location for a tape or file folder. The present invention meets these needs.